Vibration absorber

ABSTRACT

A system for absorbing vibration created by operation of an engine of the present invention includes a first plate driven by an engine shaft and a torque transmitting device for transferring torque from the engine shaft to a transmission input shaft. The system includes a first vibration absorber and a second vibration absorber. The first vibration absorber includes at least one selectively moveable mass. The second vibration absorber includes at least one biasing member and generally opposing ends. The first vibration absorber is configured to absorb vibrations created at a first harmonic of the engine and the second vibration absorber is configured to absorb vibrations created at multiple harmonics of the engine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/302,043 filed on Feb. 5, 2010. The disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to a system for absorbing vibrationcreated by operation of an engine, and in particular to a systemincluding a first vibration absorber configured to absorb vibrationscreated at a first harmonic of the engine, and a second vibrationabsorber configured to absorb vibrations created at multiple harmonicsof the engine.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

Centrifugal Pendulum Vibration Absorbers (CPVAs) are typically used toreduce torsional vibrations in rotating machine components. For example,a rotating member such as a shaft includes several CPVAs, where eachCPVA has a pendulum mass that oscillates as the shaft rotates. Themovement of the pendulum masses counteract torque fluctuations that aretransmitted from the engine to the shaft as the shaft rotates, whichreduces the torsional vibration of the shaft. CPVAs can be designed suchthat the oscillation frequency of the pendulum mass matches the enginecombustion frequency at any engine operating speed. However, matchingthe oscillation frequency with the engine combustion frequency does notalways provide suitable vibration reduction in automotive vehicles. Thisis because frequency characteristics of automotive engines in motorvehicles are influenced by axle stiffness and transmission inertias aswell as engine RPM.

As a result, spring dampers are sometimes used instead of CPVAs toattenuate torsional vibrations transmitted by automobile engines.However, one drawback is that spring dampers are generally onlyeffective within a predetermined frequency range that is often narrow.The design tradeoff of having to tune the spring dampers for a specificfrequency range results in that they are generally not able to providesufficient dampening at lower engine speeds such as when the engineoperates at idle.

While current CPVAs and spring dampers achieve their intended purpose,there is a need for a new and improved vibration dampening system whichexhibits improved performance from the standpoint of dampening torsionalvibrations at a variety of engine speeds.

SUMMARY

The present invention provides a system for absorbing vibration createdby operation of an engine. The system includes a first plate driven byan engine shaft and a torque transmitting device for transferring torquefrom the engine shaft to a transmission input shaft. The system includesa first vibration absorber and a second vibration absorber. The firstvibration absorber includes at least one selectively moveable mass. Thesecond vibration absorber includes at least one biasing member andgenerally opposing ends. The first vibration absorber is configured toabsorb vibrations created at a first harmonic of the engine and thesecond vibration absorber is configured to absorb vibrations created atmultiple harmonics of the engine.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a schematic view of an exemplary vibration absorber systemincluding a first set of vibration absorbers and a second set ofvibration absorbers;

FIG. 2A is a cross sectioned view of the vibration absorber systemillustrated in FIG. 1;

FIG. 2B is a cross sectioned view of an alternative embodiment of avibration absorber system including a first set of vibration absorbersand a second set of vibration absorbers;

FIG. 3A is a schematic illustration of the vibration absorber systemillustrated in FIG. 2A;

FIG. 3B is a schematic illustration of the vibration absorber systemillustrated in FIG. 2B;

FIG. 4A is a schematic illustration of an alternative embodiment of avibration absorber system;

FIG. 4B is a schematic illustration of another embodiment of a vibrationabsorber system;

FIG. 5A is a schematic illustration of yet another embodiment of avibration absorber system;

FIG. 5B is a schematic illustration of an embodiment of a vibrationabsorber system;

FIG. 6A is a schematic illustration of another embodiment of a vibrationabsorber system; and

FIG. 6B is a schematic illustration of yet another embodiment of avibration absorber system.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Withreference to FIG. 1, a vibration absorber system is generally indicatedby reference number 10. The vibration absorber system 10 includes afirst rotating member or plate 12 and a first set of vibration absorbers14 that are slidingly connected with the first plate 12. Each of thefirst vibration absorbers 14 include a selectively moveable pendulummass 16. FIG. 1 illustrates the first set of vibration absorbers 14 ascentrifugal pendulum vibration absorbers (CPVAs), however othervariations of vibration absorbers that employ selectively moveablemasses may be used as well. The first plate 12 is driven by an engine(not shown), or other torque producing machine to provide a drivingtorque to the first plate 12. The first plate 12 is any plate thatmounts to an output shaft 18 (FIG. 2) of the engine such as, forexample, a flywheel. In the present embodiment, the vibration absorbersystem 10 is employed in an automotive engine.

The vibration absorber system 10 also includes a second rotating plate20 and a second set of vibration absorbers 22 that are connected to thesecond plate 20. In the example provided, the second rotating plate 20is part of a torque transmitting device 24 (FIG. 2) such as, forexample, a torque converter of an automatic transmission or a clutch ofa manual transmission. However, it should be appreciated that the secondrotating plate 20 may be various other components without departing fromthe scope of the present invention. The second set of vibrationabsorbers 22 are a plurality of biasing members 28 such as, for example,spring dampers that employ a coil spring. However, one of skill in theart will appreciate that other types of biasing members can be used aswell such as, for example, resilient members constructed from anelastomer.

Each of the first set of vibration absorbers 14 are circumferentiallyarranged in a substantially symmetrical pattern around a rotational axisA-A of the first plate 12. In the present embodiment, four vibrationabsorbers 14 are included with the vibration absorber system 10, howeverthose skilled in the art will appreciate that any number of vibrationabsorbers may be used. The present embodiment also illustrates each ofthe first vibration absorbers 14 corresponding with one of the secondvibration absorbers 22 such that there are an equal number of firstvibration absorbers 14 and second vibration absorbers 22. However, anunequal number of first vibration absorbers 14 and second vibrationabsorbers 22 may be used as well.

The masses 16 of the first set of vibration absorbers 14 are eachslidingly engaged with the first plate 12, where each mass 16 includesat least one aperture 40 located within the mass 16. A correspondingpost or pin 42 connected to the first plate 12 is provided for eachaperture 40, where each aperture 40 receives at least one of the posts42. A portion of an inner surface 46 of each aperture 40 contacts aportion of an outer surface 48 of the post 42. When the first plate 12is at rest, the masses 16 each remain generally stationary and do notmove substantially. However, each mass 16 oscillates or travels aboutthe corresponding post 42 when the first plate 12 rotates about the axisA-A. Specifically, as the mass 16 travels about the corresponding posts42, a portion of the outer surface 48 of the posts 42 slide about aportion of the inner surface 46 of the apertures 40. Each mass 16travels about a specific path that is determined by the movement of themass 16 about the corresponding posts 42. The movement of the masses 16along the paths counteract at least some of the torque fluctuations thatare created as the engine operates, which thereby reduces torsionalvibration.

In one embodiment, each of the masses 16 include generally identicalpaths, where the masses 16 move in unison with one another. The masses16 travel in synchronicity with one another if the engine produces atorsional vibration that is of a single harmonic order. Alternatively inanother embodiment, the first vibration absorbers 14 are configured toabsorb torsional vibrations that have at least two different harmonicorders. For example, the engine can produce torsional vibrations of atleast two different harmonics due to the firing sequence of the engine'sspark plugs. In another example, the engine produces torsionalvibrations that have different harmonics if an engine operates on lessthan all of the cylinders during an improved fuel efficiency mode ofoperation. For example, if an eight cylinder engine switches to a fuelefficiency mode only a portion of the eight cylinders are actively firedto provide engine power. This improved fuel efficiency mode of operationimproves the fuel economy of the engine. The engine produces torsionalvibrations of a different harmonic content when operating with eightcylinders when compared to the torsional vibrations created as theengine operates on six cylinders.

If the engine produces torsional vibrations of at least two differentharmonic orders, at least one of the masses 16 travel at a differentfrequency about the path when compared to the remaining masses 16. Thatis, each of the masses 16 do not travel in synchronicity with oneanother. Instead, one of the masses 16 travels at a first engine firingfrequency about the path to attenuate torsional vibrations created at afirst frequency, and the remaining masses 16 travel at a second or otherharmonic of the engine firing frequency about the path to attenuatetorsional vibrations created at the particular harmonic.

Referring to FIGS. 1 and 2A, the biasing members 28 are secured in placewithin a torsion vibration damper assembly 26 and are circumferentiallyspaced about the axis A-A. In the embodiment as illustrated in FIG. 1,the biasing members 28 are oriented linearly about the axis A-A.However, the biasing members 28 can also be oriented arcuately about theaxis A-A instead. The biasing members 28 are compressible to absorbtorsional vibrations that are created during engine operation.Specifically, referring to FIG. 1, the biasing members 28 can be urgedinwardly in the direction R-R to attenuate torsional vibrations createdby rotation of the first plate 12.

Turning to FIG. 2A, the torsion vibration damper assembly 26 has abiasing member retainer plate 30 that is used for securing the biasingmembers 28 in place. The retainer plate 30 is located at a first end 50of the torsion vibration damper assembly 26. Referring to FIG. 1, theretainer plate 30 includes a series of recesses or damper pockets 54circumferentially located and contoured to retain one of the biasingmembers 28. Each of the end sections 56 of the biasing member 28 areseated against the edges 58 of the damper pocket 54, where the endsections 56 of the biasing member 28 react against the edges 58 of thedamper pocket 54 to attenuate torsional vibrations created by vibrationof the first plate 12.

In the embodiment as illustrated in FIG. 2A, the first end 50 of thetorsion vibration damper assembly 26 is connected to the first plate 12by a fastener 60 connecting the biasing member retainer plate 30 withthe first plate 12. A second end 52 of the torsion vibration damperassembly 26 is connected to the second plate 20, where a portion 62 ofthe second plate 20 curves inwardly towards and connects to a portion ofthe biasing member 28, thereby creating a connection between the torsionvibration damper assembly 26 and the second plate 20. The secondrotating plate 20 is part of a housing for the torque transmittingdevice 24. The fastener 60 is any fastening device that secures theretainer plates 30 to either the first plate 12 or the second plate 20,such as, for example, a bolt or a screw. Although FIG. 2A illustratesthe fastener 60, those skilled in the art will appreciate that othertypes of fastening approaches may be used instead for the retainer plate30 such as, for example, a splined engagement.

FIG. 2B is an alternative embodiment of a vibration absorber system 110including a first rotating plate 112 and a first set of vibrationabsorbers 114 that each include a selectively moveable pendulum mass116. The vibration absorber system 110 also includes a second plate 120that is part of a torque transmitting device 124 such as, for example, atorque converter housing for an automatic transmission, or a clutchhousing for a manual transmission. The second plate 120 of the torquetransmitting device 124 is connected to a torsion vibration damperassembly 126 that secures and retains a second set of vibrationabsorbers 122 that are biasing members 128.

The first plate 112 is driven by an output shaft 118 that is acrankshaft of the engine, where the first plate 112 is connected to thesecond plate 120. In the embodiment as illustrated, a plurality offasteners 170 connect the first plate 112 to the second plate 120,however those skilled in the art will appreciate that other fasteningapproaches, such as a splined engagement, may be used as well. Thesecond plate 120 is part of a first end 150 of the torsion vibrationdamper assembly 126, and a retainer plate 130 is located at a secondopposing end 152 of the torsion vibration damper assembly 126. A portion162 of the second plate 120 curves inwardly to connect to the biasingmember 128 and creates a connection between the torsion vibrationabsorber assembly 126 and the torque transmitting device 124. Thetorsion vibration absorber assembly 126 also secures a generallycylindrical hub 180 that is oriented along the axis A-A and includes aninner surface 182 that is configured for receiving an input shaft 190 ofa transmission (not shown). In one embodiment, the inner surface 182includes a plurality of splines that are configured to receive andsecure the input shaft 190 in place within the hub 180.

FIGS. 3A-3B are schematic illustrations of the embodiments illustratedin FIGS. 2A-2B of the vibration absorber system 10 and 110. Turning toFIG. 3A, an engine 100 is connected to the first plate 12, where thefirst plate 12 is a plate that mounts to an output shaft 18 (FIG. 2A) ofthe engine 100. The first set of vibration absorbers 14 are slidinglyconnected with the first plate 12, where each of the first vibrationabsorbers 14 include a selectively moveable pendulum mass 16. Thetorsion vibration damper assembly 26 is connected at the first end 50 tothe first plate 12. The second end 52 of the torsion vibration damperassembly 26 is connected to the second plate 20, where the secondrotating plate 20 is part of a housing for the torque transmittingdevice 24. The second set of vibration absorbers 22 that include thebiasing member 28 connect the first plate 12 to the second plate 20. Thetorque transmitting device 24 is connected to an input shaft of thetransmission 102. The transmission 102 is connected to an axle 104 of avehicle 106.

Turning to FIG. 3B, an engine 200 is connected to the first plate 112.The first set of vibration absorbers 114 are slidingly connected withthe first plate 112, where each of the first vibration absorbers 114include a selectively moveable pendulum mass 116. The torquetransmitting device 124 is connected to the first plate 112. The torquetransmitting device 124 includes the second plate 120, where the secondplate 120 is part of the first end 150 of the torsion vibration damperassembly 126. The second set of vibration absorbers 122 that include thebiasing member 128 connect the second plate 120 to the retainer plate130 located at the second opposing end 152 of the torsion vibrationdamper assembly 126. The torsion vibration absorber 126 receives theinput shaft 190 (FIG. 2B) of a transmission 202. The transmission 202 isconnected to an axle 204 of a vehicle 206.

FIGS. 4A-4B are schematic illustrations of alternative embodiments of avibration absorber system 210 and 310 that include a third set ofvibration absorbers. Turning to FIG. 4A, an engine 300 is connected to afirst plate 212, where the first plate 212 mounts to an output shaft(not shown) of the engine 300. A first set of vibration absorbers 214are slidingly connected with the first plate 212, where each of thefirst vibration absorbers 214 include a selectively moveable pendulummass 216. A second set of vibration absorbers 222 include a firstbiasing member 228 that connects the first plate 212 to a second plate220. In one embodiment, the first biasing member 228 is a generallystraight coil spring, however in another embodiment the spring may bearcuate as well. The second plate 220 is an inertial disk that isconnected to a torque transmitting device 224. The torque transmittingdevice 224 includes a housing that includes a third plate 238. The thirdplate 238 is part of a first end 250 of a torsion vibration damperassembly 226 that is a third vibration absorber 270.

The torsion vibration damper assembly 226 includes a second biasingmember 268 and a biasing member retainer plate 230. The retainer plate230 is located at a second end 252 of the torsion vibration damperassembly 226. The torsion vibration absorber 226 is connected to atransmission 302, where in one embodiment the torsion vibration absorber226 includes a hub (not shown) for receiving an input shaft of thetransmission 302. However, it is understood that other approaches may beused as well to connect the torsion vibration absorber 226 to thetransmission 302. The transmission 302 is connected to an axle 304 of avehicle 306.

FIG. 4B is an alternative embodiment of the vibration absorber system210 illustrated in FIG. 4A. The vibration absorber system 310 is similarto the vibration absorber 210, except that there are a plurality offirst vibration absorbers 314 that are configured to absorb torsionalvibrations that have at least two different harmonic orders.Specifically, the vibration absorber system 310 includes an engine 400is connected to a first plate 312, where the first plate 312 mounts toan output shaft (not shown) of the engine 400. The first set ofvibration absorbers 314 are slidingly connected with the first plate312, where each of the first vibration absorbers 314 include aselectively moveable pendulum mass 316. At least one of the masses 316travel at a different frequency when compared to the remaining masses316. That is, each of the masses 316 do not travel in synchronicity withone another.

The vibration absorber system 310 further includes a second vibrationabsorber 322 including a first biasing member 328 that connects thefirst plate 312 to a second plate 320. The second plate 320 is aninertial disk that is connected to a torque transmitting device 324. Thetorque transmitting device 324 includes a housing that includes a thirdplate 338. The third plate 338 is part of a first end 350 of a torsionvibration damper assembly 326 that is a third vibration absorber 370.The torsion vibration damper assembly 326 includes a second biasingmember 368 and a biasing member retainer plate 330. The retainer plate330 is located at a second end 352 of the torsion vibration damperassembly 326. The torsion vibration absorber 326 is connected to atransmission 402. The transmission 402 is connected to an axle 404 of avehicle 406. It should be noted that although FIGS. 4A-4B illustratetorque transmitting devices 224 and 324, in an alternative embodimentthe torque transmitting devices 224 and 324 may be omitted from thevibration absorber systems 210 and 310.

In the embodiments illustrated in FIGS. 1-4B, the first set of vibrationabsorbers 14,114, 214, 314 are slidingly connected with the first plate12, 112, 212, 312. However, the first set of vibration absorbers canalso be engaged with other components of a vehicle as well, which isillustrated as vibration absorbers 410, 510, 610 and 710 in FIGS. 5A-6B.Turning now to FIG. 5A, an engine 500 is connected to a first plate 412,where the first plate 412 mounts to an output shaft (not shown) of theengine 500. A torque transmitting device 424 is connected to the firstplate 412. The torque transmitting device 424 includes a second plate420, where the second plate 420 is part of a first end 450 of a torsionvibration damper assembly 426 that is a second vibration absorber 422.The torsion vibration absorber 426 includes a second end 452 that isconnected to a transmission 502.

The torsion vibration damper assembly 426 includes a biasing member 428and a biasing member retainer plate 430. The retainer plate 430 islocated at the second end 452 of the torsion vibration damper assembly426. In one embodiment, an input shaft of the transmission 502 isreceived by a hub of the torsion vibration absorber assembly 426,however it is understood that the transmission 502 may be connected tothe torsion vibration damper assembly 426 using other approaches aswell. A first set of vibration absorbers 414 are slidingly connectedwith an input shaft of the transmission 502, where each of the firstvibration absorbers 414 include a selectively moveable pendulum mass416. The transmission 502 is connected to an axle 504 of a vehicle 506.

Turning now to FIG. 5B, an engine 600 is connected to the first plate512, where the first plate 512 mounts to an output shaft of the engine600. The first plate 512 is a first mass that is part of a torsionvibration absorber illustrated as a dual mass flywheel 526. The dualmass flywheel 526 is a second mass that is a second plate 520. A firstset of vibration absorbers 514 are slidingly connected with the secondplate 520, where each of the first vibration absorbers 514 include aselectively moveable pendulum mass 516. The second plate 520 iselastically coupled to the first plate 512 by a second set of vibrationabsorbers 522. In the embodiment as illustrated, the second set ofvibration absorbers 522 are a plurality of biasing members 528. The dualmass flywheel 526 is connected at a first end 550 to a crankshaft of theengine 600 by the first plate 512. A second end 552 of the dual massflywheel 526 is the second plate 520, where the second rotating plate520 connects to a torque transmitting device 524. The torquetransmitting device 524 is connected to an input shaft of a transmission602. The transmission 602 is connected to an axle 604 of a vehicle 606.

Turning now to FIG. 6A, an engine 700 is connected to a vibrationabsorber 610 by a first plate 612, where the first plate 612 mounts toan output shaft (not shown) of the engine 700. A first biasing member628 connects the first plate 612 to a second plate 620. In oneembodiment, the first biasing member 628 is a generally straight coilspring, however in another embodiment the spring may be arcuate as well.The second plate 620 is an inertial disk that is connected to a torquetransmitting device 624. A first set of vibration absorbers 614 areslidingly connected with the second plate 620, where each of the firstvibration absorbers 614 include a selectively moveable pendulum mass616. A second set of vibration absorbers 622 include the first biasingmember 628. The torque transmitting device 624 includes a housing thatincludes a third plate 638. The third plate 638 is part of a first end650 of a torsion vibration damper assembly 626 that is a third vibrationabsorber 670.

The torsion vibration damper assembly 626 includes a second biasingmember 668 and a biasing member retainer plate 630. The retainer plate630 is located at a second end 652 of the torsion vibration damperassembly 626. The torsion vibration absorber 626 is connected to atransmission 702, where in one embodiment the torsion vibration absorber626 includes a hub (not shown) for receiving an input shaft of thetransmission 702. However, it is understood that other fasteningapproaches may be used as well to connect the torsion vibration absorber626 to the transmission 702. The transmission 702 is connected to anaxle 704 of a vehicle 706.

FIG. 6B is an alternative embodiment of the vibration absorber system710 illustrated in FIG. 6A. The vibration absorber system 710 is similarto the vibration absorber 710, except that there are a plurality offirst vibration absorbers 714 that are configured to absorb torsionalvibrations that have at least two different harmonic orders.Specifically, the vibration absorber system 710 includes an engine 800is connected to a first plate 712 mounts to an output shaft (not shown)of the engine 800. The second plate 720 is an inertial disk that isconnected to a torque transmitting device 724. The first set ofvibration absorbers 714 are slidingly connected with the second plate720, where each of the first vibration absorbers 714 include aselectively moveable pendulum mass 716. At least one of the masses 716travel at a different frequency when compared to the remaining masses716. That is, each of the masses 716 do not travel in synchronicity withone another. A second set of vibration absorbers 722 that include afirst biasing member 728 connects the first plate 712 to a second plate720.

The torque transmitting device 724 includes a housing that includes athird plate 738. The third plate 738 is part of a first end 750 of atorsion vibration damper assembly 726. The torsion vibration damperassembly 726 is a third vibration absorber 770 includes a second biasingmember 768 and a biasing member retainer plate 730. The retainer plate730 is located at a second end 752 of the torsion vibration damperassembly 726. The torsion vibration absorber 726 is connected to atransmission 802. The transmission 802 is connected to an axle 804 of avehicle 806.

Referring to FIGS. 1-6B, the first set of vibration absorbers 14, 114,214, 314, 414, 514, 614, and 714 each have masses 16, 116, 216, 316,416, 516, 616, and 716 that counteract at least some of the torquefluctuations created as the engine operates, especially at lower enginespeeds that occur during idling. The second vibration absorbers thatinclude the biasing member 28, 128, 228, 328, 428, 528 628 and 728 areemployed to attenuate torsional vibrations that occur above the idlingspeed of the engine.

At least some types of torsional vibration absorbers are generally onlyeffective to attenuate torsional vibrations that occur either at lowerengine speeds, such as idle speed, or at higher engine speeds aboveidle. In contrast, the vibration absorber system 10, 110, 210, 310, 410,510, 610, and 710 employs the first set of vibration absorbersconfigured to attenuate torsional vibrations at the first harmonic ofthe engine firing frequency. The second set of vibration absorbers areconfigured to attenuate torsional vibrations that are created atmultiple harmonics of the engine. Moreover, in at least someembodiments, the vibration absorber system may further include a thirdvibration absorber as well. As a result, the vibration absorber systemattenuates torsional vibration created at all engine speeds, unlike someof the conventional torsional vibration absorbers that are currentlyavailable.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. An apparatus for absorbing vibration andtransmitting a torque between an output of an engine and an input of atransmission of a vehicle, the apparatus comprising: a first memberinterconnected with the output of the engine and including at least oneretaining member and at least one alternate retaining member; a firstvibration absorber including at least one mass and at least onealternate mass, the mass supported by the retaining member of the firstmember and the alternate mass supported by the alternate retainingmember of the first member, wherein the mass has a predefined movementpath with respect to the first member when the first member is rotatingand the alternate mass has a predefined alternate movement path withrespect to the first member when the first member is rotating, whereinthe mass absorbs a portion of the vibrations through the first memberfrom the engine to the transmission at a first range of engine speedsthe alternate mass absorbs a portion of the vibrations through the firstmember from the engine to the transmission as the alternate mass movesalong the alternate movement path at a third range of engine speeds; anda second vibration absorber including at least one biasing member havinga first end interconnected with the first member and a second endinterconnected with the input of the transmission, wherein the biasingmember is selected to absorb a portion of the vibrations through thesecond vibration absorber from the engine to the transmission at asecond range of engine speeds, and wherein the speeds of the secondrange are lower than the speeds of the first range of engine speeds andthe third range of engine speeds are greater than engine speeds of thefirst range of engine speeds.
 2. The apparatus of claim 1 wherein thebiasing member is a coil spring.
 3. The apparatus of claim 1 wherein thefirst member is a flywheel.
 4. The apparatus of claim 1 wherein thefirst vibration absorber is a centrifugal pendulum vibration absorberand the at least one mass defines an aperture having an aperture surfaceengaged with the retaining member of the first member, and wherein aprofile of the aperture surface defines the movement path of the mass.5. The apparatus of claim 1 further including a torque transmittingdevice having an input interconnected with the first member and anoutput interconnected with the input of the transmission, wherein thetorque transmitting device is one of a clutch and a torque converter. 6.The apparatus of claim 5 wherein the first end of the biasing member isdirectly connected to the first member, the input of the torquetransmitting device is directly connected to the second end of thebiasing member, and the output of the torque transmitting device isdirectly connected to the input of the transmission.
 7. The apparatus ofclaim 5 wherein the input of the torque transmitting device is directlyconnected to the first member, the output of the torque transmittingdevice is directly connected to the first end of the biasing member, andthe second end of the biasing member is directly connected to the inputof the transmission.
 8. The apparatus of claim 5 further including athird vibration absorber including at least one alternate biasing memberhaving a first end directly connected to the output of the torquetransmitting device and a second end directly connected to the input ofthe transmission, wherein the first end of the biasing member of thesecond vibration absorber is directly connected to the first member andthe second end of the biasing member of the second vibration absorber isdirectly connected to the input of the torque transmitting device. 9.The apparatus of claim 5 further including a third vibration absorberincluding at least one alternate biasing member having a first enddirectly connected to the output of the engine and a second end directlyconnected to the first member, wherein the input of the torquetransmitting device is directly connected to the first member, theoutput of the torque transmitting device is directly connected to thefirst end of the biasing member of the second vibration absorber, andthe second end of the biasing member of the second vibration absorber isdirectly connected to the input of the transmission.